Double-storey extensions for homes in Clevedon
We design and build double-storey extensions for houses in Clevedon, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in ClevedonFrom £38,500 inc VAT
- PlanningUsually a householder application
- Build time16–24 weeks on site
- Postcode districtsBS21
Working in Clevedon
Postcode districts we cover around Clevedon include BS21. We also work in nearby Nailsea (4 miles), Portishead (5 miles), Weston-super-Mare (8 miles), Burnham-on-Sea (15 miles).
Just over the Gloucestershire border, Kingswood is about 15 miles away. South West homes range from terraced streets in the cities to stone cottages and bungalows in the countryside, and conservation areas are common in historic centres.
Included in a typical project
- Insulation, plastering, electrics and plumbing to finish
- Measured survey, design and planning drawings
- Breaking through at both levels, stairs and landing changes where needed
- Building regulations drawings and structural design
Will the council need to approve it?
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
What should I budget for a double-storey extension in Clevedon?
For Clevedon we adjust our national guide rates by ×1.02, the factor we use for South West England. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Clevedon: £1,580 to £3,060 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m, two floors 24 m² | £38,500 – £46,500 | £44,000 – £58,000 | £56,000 – £73,500 |
| 4 m × 4 m, two floors 32 m² | £50,500 – £60,500 | £58,500 – £77,000 | £75,000 – £98,000 |
| 4 m × 6 m, two floors 48 m² | £75,500 – £91,000 | £88,000 – £115,500 | £112,500 – £147,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
What happens next
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Your questions about a double-storey extension in Clevedon
Do I need building regulations approval in Clevedon?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Clevedon, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Do you cover all of Clevedon?
Yes. We cover Clevedon and the surrounding parts of Somerset. Site visits are free and there is no obligation.
Do I need a Party Wall Agreement?
If you are in England or Wales and the work involves a shared wall or digging foundations close to a neighbour, the Party Wall etc. Act 1996 applies and notices must be served before work starts. We tell you which notices are needed.
Does a double-storey extension need planning permission?
Often, yes. In England a two-storey rear extension can be permitted development only if it projects no more than 3 m and sits at least 7 m from the rear boundary, with matching roof pitch and obscure side windows. Side extensions over one storey always need planning permission. We confirm the route at the survey.
Book a free site visit in Clevedon
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.